An antenna is a transducer, which transmits or receives electromagnetic waves. Antennas include one or more elements, which are conductors that can radiate and or receive electromagnetic waves. These elements are often referred to as radiators with a collection of radiators referred to as an aperture. When transmitting, an alternating current is created in the element(s) by application of a voltage at the terminals of the antenna, which causes the element(s) to radiate an electromagnetic field. When receiving, an electromagnetic field from a remote source induces an alternating current in the elements generating a corresponding voltage at the terminals of the antenna.
FIG. 1 shows a diagram of a conventional antenna array 100. The antenna array 100 includes several linear arrays 104 housed in a non-metallic radome 102. Here, each linear array 104 is arranged vertically with spacing between each other, which is determined by the desired resonant frequency of the antenna array 100. Each linear array 102 is connected to its associated radio frequency (RF) electronics circuitry contained in an external RF electronics module 108, via an antenna feed 106. The RF electronics module 108 is connected to external systems via a connection 110 for power, control, and communications connections; and may be physically mounted on the radome 102, or may be located remotely or outside of the antenna array 100.
An Electronically Scanned Array (ESA) is a type of phased array antenna, in which transceivers include a large number of solid-state transmit/receive modules. In ESAs, an electromagnetic beam is emitted by broadcasting radio frequency energy that interferes constructively at certain angles in front of the antenna.
Modern Radar, Jammer and Communications antenna systems often require wideband frequency capability within constrained volume allocations. Electronically Scanned Array (ESA) antenna designs provide dense-packed, high-reliability electronics, but ESA component limitations typically require that wideband frequency applications be broken up into multiple bands for hardware implementation. These bandwidth-limited components may include circulators, power amplifiers, or manifolding, and wideband partitioning typically results in the need for multiple antenna assemblies with each additional antenna requiring volume, weight, and cost allocations.
Typical wideband antenna applications use separate antenna assemblies for each performance frequency band as shown in FIG. 2, but each additional antenna requires additional volume, weight, and cost allocations. FIG. 2 illustrates two antenna array assemblies for two different bands, according to conventional approaches. As depicted, one antenna assembly including its own aperture is used for band 1 and a separate antenna assembly including its own aperture is used for band 2.
The present invention provides a solution to the wideband antenna application problem by packaging multi-band electronic layers in one antenna assembly using a shared aperture.